Ghost Illusion Created in Lab with New Robot

A participant works with the two-part robot that creates the ghost illusion

Sometimes, people report having felt a strange, unseen presence around them — and they may attribute it to a ghost. Now, in a new study, scientists describe how the "ghost" is an illusion made by the brain.

In experiments, the researchers were able to trick the participants' brains into creating the eerie sensation.

"The sensation that somebody is nearby when no one is actually present is called 'the feeling of a presence,'" the researchers said. "Although people do not see the 'presence,' they may describe its spatial location and frequently turn around or offer food to the invisible presence."